hallmark

A hallmark is an official mark or stamp indicating the purity and authenticity of precious metals. Traditionally applied to gold, silver, and platinum objects, a hallmark may include the fineness mark (such as 925 for sterling silver), a maker's mark, an assay office mark, and sometimes a date letter. Hallmarks help verify content, origin, and quality and serve as legal and consumer protection in many jurisdictions.

The practice originated in medieval Europe with regulated assay offices and guilds. The term hall mark is thought to derive from the hall or hall office where the marking occurred, or from the authority of city or guild halls. In the United Kingdom, hallmarking is overseen by assay offices in London, Birmingham, Sheffield, and Edinburgh, and British hallmarks typically combine the fineness mark, the maker's mark, and the assay office mark, along with a date letter.

Beyond metal purity, hallmark is widely used metaphorically to denote a distinguishing feature or hallmark characteristic that defines something or someone—an attribute regarded as a typical, high-quality trait. For example, elegance is a hallmark of the designer's work.

In popular culture, Hallmark is also a brand name associated with Hallmark Cards, founded in 1910 in the United States, and with the Hallmark Channel and related networks, which produce family-friendly entertainment and seasonal programming. The term's use as a brand contrasts with its generic meaning.